Roof structure



Oct. 13, 1959 I e. R. KIEWITT 2,908,236

ROOF STRUCTURE Filed Dec. 8, 1955 Q 3 Sheets-Sheet l Oct. 13, 1959 Filed Dec. 8, 1955 G. R. KIEWITT ROOF STRUCTURE 3 Shee ts-Sheet 2 O 13, 1959 G. R. KIEWITT 2,908,236 ROOF STRUCTURE Filed Dec. 8, 1955 s Sheets-Sheet s V United States Patent 2,908,236 ROOFVSTRUCTURE Gustel R. Kiewitt,iLadue,'Mo. Application December'S, 1955, Serial No. 551,766 1 Claim. euros-1 This :invention relates to roof structures, .more particularly to roof structures of dome shape. r

Among the .several objects of the invention .may b noted the provision of a roof framework having the shape of a dome which may be constructed more economically than prior dome-type frameworks. .of comparable capacity; the provision of a roof frameworkv of the class described which is .of such construction that .the .dead load is substantially uniformly distributed in the framework throughout the surface area of the dome, and also such as to enable simplification o'fstress analysis; the provision of a roof framework of this class which is .of such construction as to enable the .substan- .tial use of approximately duplicate members (i.e;', members :havingthe same cross-section and approximately the same length), thereby simplifying the fabricationof the framework; the provision of a roof framework of this class which is of such construction that each member of the framework is-subject only to direct loads, and not subject to 'any moments .except for those whichm'ay occurxbecause of local loadings and secondary actions; and the provision of a framework of the class described which may be readily fabricated of conventional com- 'mereially available structural members and readily erected in the field. Other objects and features will be in part apparent and'in part pointed out hereinafter.

'The invention according-1y comprises the construction hereinafter described, the scope of the invention being-indicated in the following claim. I

In the accompanying drawings, in which several of var-ious possible embodiments of the invention are illustrated, p

Fig. 1 is a diagrammatic work of this invention;

Fig. 2 is a central vertical section taken on line 2-2 of Fig. 1; e

Fig. 3 is adetail of a supporting inemberof the Fig. 1 framework; 1 i

plan view ofa roof frameframework has the shape of a dome and is of isometrical pattern with respect to the vertical axis of the dome. The-term=idome as used herein means a roof structure shaped according to a curved surface of revolutiomas for example it may be a part-spherical orcurved dome,

2,908,236 Ratented Oct. 13, 1959 7'2 proximately equiangular curved 'segme'nts' around the center of the domeru lt furthercomprisesan cuter circumferential member or firings located: on :a parallel 0f the dome concentric withqthe vertical of the dome and defining-the lower edge of: thewdome. .;The:meridian members are connected totheouter'circumferential :memberl.or.:ringat outerijoints indicated cat 7.:

The framework nfurther tcompr ises ta -;pluralit-y=of inner circumferential, members or 'rings located on ,2 parallels of .the dome concentric with thevertical axis of-the-,-dome, and connected "to the meridian members, :at inner joints. As shown inFig. :1, which illustrates a -:relatively small framework, there are two such inner circumferential members or rings, the innennostbf these being designated 9 and the=circumferential member or-ringwhich lies be tween the ring ;9':and theyring-5 being designated 11.

Ring '11 islocated'centrally between the outer-ring Sand triangulate between apex 3 3 and ring 9, between rings Fig. 4 is an enlargement of one *sector of the 'framea part elliptical curved dome, or the "like. The framework is shown to comprise a plurality of projectively in- :tersecting -meridian'members 3 located on ithe domeand dividing the'dome into a plurality of equal angled sectors, that is, the meridianmembers form apmeridians of conventional structural" sections.

9 and 1-1, and between rings ll and 5,. FIfhese ribs .are located on lines indicated at -17 and:19; extending from the inner joints :13 and -15 at ;one side of -the.,sector-,(,its left side as illustrated in: Fig. 4) to thelouter ring 5 approximately parallel tQ-the other .z(right) side of the sector, and on lines indicated. ;at;,21 and ,23 extending from the inner joints-.1 3. and lfiat the -other (right) side of the sector to the -outer. rin g 5 approximately parallel to the one side, {the left :side) of the sector. The lines 11 and 21 intersect ,one another and intersectthe intermediate ring 1 1 midway. between the two meridian members 3 of thesector, the point of intersection being designated 25. The lines 17 and 21 intersect the outer ring 5 at the one-third ,pointsoftheportion of member 5 betweenthe two meridian members 3 ,of the sector, the points .of. intersection being respectively designated and 29. The line .19.,interseets the outeriring .5 and line 21 at point 2 9. The line z3fintersects'the outer ring 5 and line, 17 at point .27. Thus three chord members are ,established 'between each pair of points 7 in the outerlrin'g"5;" two chordsfbe tween each pair of points;15 in the ring 11; and ionechord between e'achlpair of points 13 in ring 9. "The .general rule, as willalso'be apparent from the Fig, 5 fQi'm.,Of the invention,'tof,be described, is that the.. nuniber of chord members 'injthe' outermost ring between each pair ofmeridians co'rrespondsfto the number of rings, and the number of chord members of each succeeding inner ring, between each ,pairfo'f meridian s, decreases by, one.

The "stated arrangement oftriangulatingribs results in innermostgpairiof' rings. Extrapolation iin regard to the use of more than jthree rings asshown' in appear below where Fig. 6 is'described p lhe framework, may be fabricated of suitable f r: ampl e ch F s, w l

em e 9 h mewsat.

shown, the outer ring may consist of a series of indi-.

the'inner ring-9,- and a section 3b connected to the inner end "of 3a by ajoint at 31 and; continuing to the apex centerQS of the dome. Sections 3b-are joined together 33 1- Theinner ring 9-isshown as consisting of individual chords 9a, eachhaving a lengthcorresponding to the lengthof the chord subtended by the two meridians ofa sector-"at the radius of-the inner fring. These chords 9a are connected at their ends to the respective meridian members 3 at the inner ring joints 13. -The intermediate ring 11 isshown as consisting of individual chords 11a, each having a length corresponding to the length of a chord subtended by the median of a sector and a'n adjoining meridian at the radius of the intermediate ring. Thus, there are two chords 11a in each sector. One of these extends from the inner ring joint '1'5jat oneside of the's'ector to a jointiat the point 25, 'and'the'otherextends from the inner ring joint 15 at the 'other side of the sectorft'o the joint at the point The lines The 215. came 17 -there aretwo-members 17a and 17b,

17aflex'tendiri'g from joint {13 ;to the joint at 25, and '17b;-extendingff rom the joint-at 25 to a joint at 27. Onj1ine'21 there is one' member (also designated 21) extending continuouslyffrom joint 13 to a joint at 29. On lines 19 and 23 there-are single members also designated'19fand 23, member 19"extending from the joint -15"at the left side of the sector to the joint at '29, memberi23; extending 'from the joint 15 at the right side "of-'afsector to the joint at'27. .The joints at 7, 13, 15', 25,127 and29 may be, of any suitable conventional 'constructionfor transmitting forces. For example, they maybe'weldedjoints; V y

' The "above-described construction is of such character thateach individuaf member of the framework is subjected. substantially only, to. direct loads, except for moments-due to secondaryactions and local loadings, the arrangement [of the. frame members permitting the full and c ontii:u1o us development of both meridian and circumferential forces; In the case of a .so-called fiat domejwhich is a dome in which the angle between the 1 vertical axisfof 'th e dome and a line drawn from the sphericahcenter of the dome tothe outer edge of the dome" is lessthanfil" 49, the outer ring 5 is in tension,

every other 'memberis in compression. The framework may be safely designed with members of comparal tivelyismall cross section, thereby to efiect substantial savings in thetot'alweight of material used in the frameeq ectors andsince the] sectors are all identical, fstr ss na ly'sis and fabrication! are simplified. Theforce 'di st rib'utionis such that all the members of the framewo rlcfexeepcforfthose "constituting the rings may have the s ame crosssection and belmade of the same stock, hereby 'Simplifyingdesign and; fabrication} Thus, as "shown tang: 2,;1

dian rinembers fasj above des crib'ed, it "is poswo rki' Since theimeridians 3 divide the framework into e e H efdepthsofhltoffthe meridian'mem hers-13a df rib 'mer nbers 17,f 21,23 arethe same. equiangular curved segments around ,thegcenteriofgthe riangulatlonfmembers approximately parallel j framef members of approximembers 43corresponding to the members 3 of Fig. 1.

mediate rings designated 51,53, 55 and 57. The inner ring joints at which rings 49, 5 1, 53, 55 and 57 are connected to the meridian members 43 are respectively designated 59, 61, 63,65. and 67. a e

Each of the sectors into which the Fig. 5 dome is divided by meridian "members 43 .is. triangulated by members located on lines indicated at 69, 71, 73, 75 and 77 extending from the joints 59, 61, 63, 65 and 67 at one side of the sector (its left side as illustrated in Fig. 6) to the outer ring 45 approximately parallel to the other (right) side of the sector, and by members located 'on lines indicated at 79, 81,- 83,..85 andx87 extending from the joints 59, 61, 63, 65 and 67 at the other (right) :side of the sector to the outer ring 45 approximately parallel .to the one side (the left side) of the sector.

The lines 69 and 79 and the ring 51 intersect at; 89. 69 and81 and the ring v53 intersect. at 91'. and 79 and the ring 53 intersect at 93 lines 69 and 83 and the ring 55. intersect at 95. The lines 71 and 81 and the ring 55' intersect at 97. The lines 73. and 79 and the ring 55 intersectat 99. The lines- 69 and 85 and the ring 57 intersect at 101. The lines 71 The lines 73 and 81 and the ring 57 .intersect at 105. The lines75 and 79 .andthe ring 57 intersect at 107. The lines 69 and 87 and the outer ring 45 intersect at 109. The lines 71 and 8S and the'outer. ring 45 intersect at 111. The lines 73 and 83 and the outer ring 45 intersectat 113.. The lines75 and 81 and the outer'ring'45intersect at 115. The lines 77 :and 79 and the :outer ring 45 intersect at 117.

lines 71 The At each of thestated intersections of the lines and the 7 dicating the ends of the respective members. Figs. '5 and 6 also show the meridian 'members 43 having their inner ends connected to a supporting ring 119 for a. lantern such as indicated at 12.1.; Figs. 5 and 6 also-illustrate. a cantilever extension 123 from the outer ring of the dome.

The framework illustrated fin; Figs. 5 and 6 has the .same characteristics as that ofFigs. 1 to 4, the principal difierence being that additional rings and triangulation members are required in view ofits greater size. Fig. 5 also illustrates the intermediate rings as being somewhat irregular due to designing the framework as much as possible with triangulation members of equal length, but it will be understood that this is not necessary, and may be dispensed with for aesthetic reasons. e H In view' of the above, it will be seen that the several objects of the invention are achieved and other advantageous resultsattained.

dome, a plurality of approximately parallel main rings concentric with the dome axis and secured tov said: me-

ridian members, said rings being spaced at approximate- 1y equal distances aleng the-,lengths of said" meridian members and comprising a pluralityof connected; chord .me u et 'sf eitir xi a y s a s h rl e umber of chord members in the outermost ringbetween each and'83 and the ring 57 intersect at. 103.

5 pair of meridian members corresponding in number to the number of rings, the chord members of each succeeding inner ring between each pair of meridian members decreasing in number by one, at least one pair of outwardly converging curved triangle-forming rib members extending from each ring, said rib members being of approximately equal lengths and constant depths throughout their said lengths, which depths substantially equal the said depths of the meridian members, the rib members of each pair converging to an apex on the next larger ring, the apexes being located between said equal chord lengths and forming a number of triangles in the spaces between adjacent meridian members and adjacent rings, the number of triangle-forming rib members between adjacent rings and meridian members progressively diifen'ng by two, the innermost pair of rings having two such triangle-forming rib members, the number of triangles formed in said spaces by said triangle-forming rib members between successively adjacent larger rings 6 corresponding to the odd numbers starting with three between said inner pair of rings. 1

References Cited in the file of this patent UNITED STATES PATENTS 2,167,048 Legarda July 25, 1939 2,773,458 Foster Dec. 11, 1956 FOREIGN PATENTS 10,56 1 Great Britain May 5, 19 13 140,073 Great Britain May 8, 1920 456,323 Germany Aug. 27, 1928 590,294 Great Britain July 14, 1947 1,036,928 France Apr. 29, 1953 OTHER REFERENCES Engineering News, July 29, 1915, volume 74, No. 5, page 208. 

